JavaScript で表示するために数値をフォーマットするにはどうすればよいですか?

<code class="javascript">var value = (100000).toLocaleString(
  undefined, // leave undefined to use the browser locale
  { minimumFractionDigits: 2 } // set the minimum number of decimal places
);

console.log(value); // Output: "100,000.00"</code>

<code class="javascript">function numberFormat(num, decimals) {
  if (decimals === undefined) decimals = 2; // default to 2 decimal places

  // Split the number into integer and fractional parts
  var parts = num.toFixed(decimals).split(".");

  // Insert commas into the integer part
  parts[0] = parts[0].replace(/(\d)(?=(\d{3})+(?!\d))/g, ",");

  // Return the formatted number
  return parts.join(".");
}

var formattedNumber = numberFormat(123456.789, 3);
console.log(formattedNumber); // Output: "123,456.789"</code>